ORIGINAL CONTRIBUTIONS

In-Hospital and Long-Term Outcomes of Patients with Acute Myocardial Infarction Undergoing Direct Angioplasty During Regular and

Nirat Beohar, MD, Raj Chandwaney, MD, Lynne M. Goodreau, RN, Charles J. Davidson, MD
Nirat Beohar, MD, Raj Chandwaney, MD, Lynne M. Goodreau, RN, Charles J. Davidson, MD
Direct percutaneous coronary angioplasty (d-PTCA) has emerged as an effective reperfusion strategy in patients presenting within the first 12 hours of an acute myocardial infarction as compared to intravenous thrombolytics.1–5 Several randomized thrombolytic trials have demonstrated that the benefit of reperfusion is strongly dependent on the time from symptom onset until treatment.6,7 This has led to concern about the potential adverse effect of the increase in time to reperfusion with d-PTCA when performed after hours for acute myocardial infarction (AMI) due to the delay in mobilization of the catheterization laboratory.8–15 Previous studies addressing this question are limited by a lack of long-term outcomes, and limited use of stents or abciximab.10,11 The purpose of this study is to compare the in-hospital and long-term outcomes for patients undergoing d-PTCA after hours to those undergoing d-PTCA during regular hours within the first 12 hours of an acute myocardial infarction. methods In-hospital and long-term outcomes of 220 consecutive patients presenting within 12 hours of ST-segment elevation AMI undergoing d-PTCA were evaluated. Time of presentation was classified as either regular hours (7:30 am to 5:00 pm) or after hours (5:00 pm to 7:30 am, weekends and holidays). AMI was defined as >= 30 minutes of typical chest pain with the presence of ST-segment elevation >= 1 mm in 2 or more contiguous electrocardiographic (ECG) leads. No patients presenting to the hospital during the period of this study received intravenous thrombolytic therapy. Written informed consent was obtained prior to d-PTCA. d-PTCA was performed using standard angioplasty technique. In patients with multivessel disease, only the culprit vessel was intervened at the time of presentation. Stents and abciximab were used at the discretion of the operator. Abciximab was the only intravenous IIb/IIIa inhibitor used. Patients receiving intracoronary stents were given ticlopidine 500 mg orally at completion of the procedure and 250 mg twice daily subsequently for 14 days. Visual assessment of the angiographic severity of stenosis and TIMI flow was made. Successful angioplasty was defined as a residual stenosis Definitions. Recurrent ischemia was defined as reinfarction or rest angina with ST-segment or T-wave changes. Reinfarction was defined as recurrent chest pain lasting more than 30 minutes with ST-T changes and either emergency angiographic confirmation of an occluded vessel or recurrent elevation of cardiac enzymes (creatine kinase elevation more than 3 times upper limit of normal with positive MB fraction). Target vessel revascularization was defined as subsequent PCI of the infarct vessel or CABG of the infarct-related artery. Statistical analysis. Baseline data were compared between the group presenting during regular hours with the group presenting after hours using the Pearson’s Chi-square tests for nominal data and Wilcoxon rank-sum tests for categorical or continuous variables. A log-rank test was used to determine the association between this time of procedure variable and the occurrence of major adverse cardiac events (MACE) overall or post discharge. A Kaplan-Meier curve of the time to MACE overall for each of these two time groups illustrates this association. RESULTS Northwestern Memorial Hospital performs approximately 100 d-PTCAs and 800 elective PTCAs per year. These cases are divided between 5 operators. Of the total cohort of 220 patients with ST-segment elevation acute myocardial infarction undergoing d-PTCA, a total of 88 (40%) presented after hours and 132 (60%) presented during regular hours. Median time to last follow-up or death was 20 months (range, 11–31 months). Demographic data are presented in Table 1. No significant differences were noted between the two groups. The median age was similar between groups (Regular Hours: 57 years (range, 49–66 years); After Hours: 57 years (range, 49–66 years). The population was predominantly male in both groups (Regular Hours: 78%; After Hours: 76%; p = 0.74). Angiographic features are presented in Table 2. PTCA was successful in 97% of the Regular Hours group and 95% of the After Hours group (p = 0.56). Stents were used in 54% of the Regular Hours group and 52% of the After Hours group (p = 0.85). Abciximab use was 70% in the Regular Hours group and 66% in the After Hours group (p = 0.55). The effect of presentation during regular hours or after hours is shown in Table 3. Presentation after hours resulted in a significant increase in the emergency room to balloon time (p
References
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